docs: def getHosts(filename=None, hostlist=None):
      """Return a list of hosts depending on the environment"""
      if filename:
          return getHostsFromFile(filename)
      elif hostlist:
          return getHostsFromList(hostlist)
      elif getEnv() == "SLURM":
          return getHostsFromSLURM()
      elif getEnv() == "PBS":
          return getHostsFromPBS()
      elif getEnv() == "SGE":
          return getHostsFromSGE()
      else:
          return getDefaultHosts()